data segment
    x dw 6
 resu dw ?
 data ends
code segment
    assume cs:code,ds:data
start:
   mov ax,data
   mov ds,ax
   mov ax,5
   mul x
   add ax,4
   mul x
   sub ax,3
   mul x
   add ax,21
   mov resu,ax
   mov ah,4ch
   int 21h
 code ends
end start